Nightly News | September 22, 2013
>>> the mass shootling at the washington navy yard is drawing new attention to the role of mental health . the mental health system in trying to prevent such violence. we've seen them before. in newtown, connecticut, and now aaron alexis in washington. troubled young men who gave warning signs but apparently fell through cracks in what some say is a flawed system. a report from our chief medical editor, dr. nancy snyderman .
>> reporter: aaron alexis had violent outbursts and told police he had anger management issues as far back as nine years but was never formally diagnosed with a mental illness . the navy contractor showed signs of a psychiatric disorder .
>> this has gone undetected and untreated until finally, it pushed them to this violent behavior.
>> reporter: one of the most recent signs, last month alexis told police in newport, rhode island , he heard voices talking to him through walls, floor and ceiling of the hotel room and could not fall asleep. the police said they sent the report to the newport naval base . but pentagon officials said it never went up the chain of command . soon after alexis did go to two v.a. hospitals but complained of and was treated for insomnia.
>> if mental health care was provided in the routine systematic way that general medical care was, ideally we would have expected that he would have been identified, diagnosed and offered treatment much earlier.
>> reporter: in fact, the nonprofit treatment advocacy center gives more than half the states a grade of c or below in their efforts to help the mentally ill before they might commit a crime.
>> we can't arrest people just because they're psychotic. they shnl be arrested any more than we would arrest someone with a heart attack. but they should get treatment.
>> reporter: while most people with mental illness never turn to violence, mental health advocates say half or more of those responsible for mass shootings in recent years have suffered from a serious mental illness . dr. michael stone of columbia university has studied the behavior and symptoms of almost 300 mass murderers. he says aaron alexis should have been hospitalized last month after hearing voices .
>> he really constituted a threat to violence, but he was not saying i'm going to go out and kill somebody. he didn't say the magic words , so to speak.
>> reporter: a caution that the system needs to do a better job of reaching the severely mentally ill before it is too late again. dr. nancy snyderman , nbc news, new york.